Products of this type, that come in form of a foam referred to as “firestop”, more particularly based on a polyurethane foam, are already known.
In this connection, it can be observed that a virgin polyurethane foam however involves the drawback of emitting flaming drops in case of a fire.
In order to overcome this drawback, it is well known to add to such a polyurethane foam flame-retardant agents, usually made from halogenated compounds. In this connection, it can be noted that it is particularly difficult to produce a foam containing such halogenated compounds and presenting satisfactory reaction and resistance to fire.
Furthermore, the use of such halogenated compounds involves environmental pollution problems and causes, upon combustion of the foam, uncontrolled discharges to the atmosphere and, more particularly, the release of large amounts of dense and toxic fumes. It can furthermore be noted that, in case a chlorine-based halogenated compound is used, the fumes of such a retarding agent combine with the water thrown out by firemen and form hydrochloric acid, which is particularly corrosive and likely to imperil these firemen.
There are also polyurethane foams that, in order to have a good fire behaviour, are made from halogenated or phosphorus-containing polyols. These polyols involve a certain number of drawbacks notably linked with polluting discharges of the aforementioned type, with a particularly high cost price and with a high viscosity that makes the use of such a polyol particularly complex.
The present invention aims to overcome the drawbacks of the firestop materials of the prior art.